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As global demand for renewable energy sources increases, solution-processable organic semiconductors have tremendous potential to enable large-scale manufacturing of lightweight, flexible and low-cost solar panels for light energy harvesting. The photoactive layers of these devices typically comprise a mixture of an electron donating polymer and an electron accepting small molecule that are co-deposited from solution onto electrodes. One of the main challenges facing the commercialization of organic solar cells is the lack of control over the morphology of the photoactive layer, which in turn leads to poor device efficiencies. Furthermore, at least 90% of the current research field uses batch spin coating methods to deposit the photoactive layer. Our research team has recently developed a novel approach to use shear forces to tune the phase separation between the electron donor, poly(3-hexylthiophene) (P3HT), and acceptor, phenyl-C61-butyric acid methyl ester (PCBM), prior to film deposition. Comprehensive rheological testing has revealed that shearing P3HT/PCBM solutions in the gel state can induce the nucleation and crystallization of both P3HT and PCBM. The strength of the gel phase was found to depend on the solvent type, but was independent of the presence, or absence of PCBM. Interestingly, replacing PCBM with a different small molecule, 6,13-bis(triisopropylsilylethinyl)pentacene (TIPS-Pentacene), significantly interfered with the crystallization of the P3HT. We also examined the incorporation of a popular processing additive, 1,8-octanedithiol (ODT). ODT preferentially dissolves PCBM and has a lower vapor pressure than the host solvent, in this case dichlorobenzene. Due to both of these properties, the presence of ODT was found to enhance the crystallization of P3HT. Rheological testing was performed to observe the effects of ODT on the gel strength of P3HT solution. It was discovered that increasing ODT concentration decreased gel strength in both the sheared system and non-sheared system. Significantly, this shearing process is compatible with continuous processing methods that will decrease the cost of fabricating organic solar cells and propel this technology towards commercialization.